1. Field of Invention
The present invention relates generally to vehicle lifts and stands. More particularly, certain embodiments of the present invention relate to pneumatically powered vehicle lifts that employ dual mechanical locking mechanisms for enhanced safety when a vehicle is being held in a raised position.
2. Discussion of the Prior Art
The maintenance of vehicles such as cars and trucks frequently requires access to the underside of the vehicles in order to permit repair of parts such as transmissions, clutches, gearing, joints, brakes, and the like. In order to reach these areas of a vehicle, a worker typically employs one or more lifting devices that are positioned beneath the vehicle chassis or wheels and actuated to lift the vehicle above the ground.
Once the vehicle has been raised to a desired height for carrying out the desired maintenance, stands are commonly positioned beneath the vehicle to support it during the repairs, and the lifting devices are removed. The stands are used in place of the lifting devices because of the added support provided by such stands, and because such stands do not allow inadvertent upward or downward shifting of the vehicle.
U.S. Pat. No. 5,484,134 discloses pneumatic lifts that also function as support stands to hold a vehicle in a lifted position while it is being worked on. The entire disclosure of the '134 patent is incorporated herein by reference. Although, the lift system of the '134 represents a significant advancement in automotive wheel lifts, the system of the '134 patent is configured to raise and hold one end of a vehicle at a time. Further, the system requires manual level control during raising and lowering.